2009: Taylor Swift, 20, & Lucas Till, 19

"We just really both liked each other ... but most relationships work out 'cause you get along and then you don't, and then you make up and it's passionate. And with us I really just liked her as a friend. That's the only reason that didn't work out."

2009: Taylor Swift, 20, & Taylor Lautner, 17

"Valentine's Day"

And here's where she started to slide.

Technically, this relationship was possibly illegal in many states as 20-year-old Swift was dating a minor.

The two met after co-starring in the year's "Valentine's Day" and never publicly admitted they were dating, but were frequently spotted spending lots of quality time together.

In October 2010, Swift revealed her crush: "Taylor Lautner. It's always going to be Taylor."

It's believed that the song "Back To December" is Swift's apology to Lautner for their breakup.

2010: Taylor Swift, 21, & John Mayer, 32

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And then the inappropriateness of Swift's dating habits peaked when she started seeing 11-years her senior and notorious playboy, John Mayer.

Neither party confirmed the romance, but they reportedly dated through February 2010.

But she does sing about it, and then the heartbroken young Swift penned the song "Dear John" about the break up.

Earlier this year, Mayer admitted that he felt "humiliated" when he heard the song, but Swift refuses to admit it's about him, telling Glamour magazine it was "presumptuous" of him to think the song was about him.

2010: Taylor Swift, 21 & Cory Monteith, 27

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After her relationship with 32-year-old Mayer, Swift took the age gap down just a few notches but cozying up to then 27-year-old "Glee" star Cory Monteith.

2011: Taylor Swift, 21 & Jake Gyllenhaal, 30

The surprising pairing had many wondering if the relationship was more of a publicity stunt, but Swift apparently had her heart broken — again — because she ended up reportedly writing many of the songs on her "Red" album about the romance.

Swift told "Good Morning America" of her rumored single about Gyllenhaal: "'All Too Well' was the hardest to write because it took me a long time to filter through everything I wanted to say ... It started out being a 10-minute song, which you can't put on an album. I had to filter it down to a story that could work in the form of a song."

2011: Taylor Swift, 21 & Zac Efron, 23

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After suffering heartbreak at the hands of two older men, Swift returned to her own age group when she reportedly (and briefly) dated Zac Efron while promoting their movie "The Lorax" in February 2011.

But Swift denies any relationship, telling Ellen DeGeneres of her latest album: "There's nothing really about Zac on the CD ... because we didn't date."

2012: Taylor Swift, 22 & Eddie Redmayne, 30

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And we're back to the 30+ set.

Swift met "My Week With Marilyn" actor Eddie Redmayne while auditioning to play Eponine in the film adaptation of "Les Miserables." (She didn't get it, he did).

"They hung out in New York City with the movie's execs," a source told Us Weekly in February. "And Taylor developed feelings for him fast."

"Taylor loved this image of a British boyfriend," the source explained, but Redmayne "wasn't interested" in a long-distance relationship.

"The elements were against them," the source told the mag. "It's a shame."

2012: Taylor Swift, 22 & Conor Kennedy, 18

After Swift initially bonded with Conor's grandmother Ethel, the singer became friendly with the younger Kennedy and was soon spotted at the famous family's compound in Hyannis Port — and reportedly even purchased a home nearby.